PUR vs ZeroWater: which is actually certified — and what does a certified gallon cost?

Last reviewed July 2026.

Same job, same shelf — but the certifications underneath are not the same. Here is PUR against ZeroWater on the only two axes we score: what the certification actually covers, and what a certified gallon costs.

• PUR: cheapest certified-for-lead filter is the PPF951K1 at $0.375/certified gallon (NSF, NSF/ANSI 42, 53, 401).
• ZeroWater: cheapest certified-for-lead filter is the ZR-002 at $1.233/certified gallon (IAPMO, NSF/ANSI 42, 53).

On certified-for-lead cost per gallon, PUR wins: $0.375 vs $1.233 — 3.3× cheaper for every gallon its certification covers.

Every model, side by side

Price per filter ÷ certified capacity in gallons. Certification data from the certifiers' public listings; the listing always wins.

The full stories: Is PUR NSF certified? · Is ZeroWater NSF certified? · what 42, 53 and 401 mean

We do not test filters — we index what accredited certifiers publish, with attribution, and make no health or treatment claims. A certification covers a specific model against a specific standard; it is not a general seal of quality. We are not affiliated with NSF International.